TWI537126B - Water - based resin coating laminated metal plate - Google Patents

Description

Water-based resin coating laminated metal sheet

The present invention relates to a black water-based resin coating laminated metal sheet for use in a casing or interior of an automobile or household electrical appliance, an exterior part, a steel furniture, or the like, and more particularly, in terms of blackness and appearance. A water-based resin coating laminated metal plate.

As an exterior part of an electronic ‧ electrical machine such as a liquid crystal television, a plasma display, or a DVD player, a black pattern design is required from the viewpoint of design and the like. Conventionally, as a ferrous metal plate, a metal plate (PCM: precoated metal) previously coated with a solvent-based black coating film is used. On the PCM coated with the black coating film, an undercoat layer (film thickness of about 3 μm) for imparting workability or corrosion resistance is laminated, and a top coat layer of a black layer containing a black pigment such as carbon black is laminated thereon. (The film thickness is about 10 μm), and the total film thickness of the undercoat layer and the top coat layer is usually set to be slightly thicker than about 10 to 20 μm. However, if the film thickness is increased, a large amount of energy is consumed due to an increase in the amount of use of the coating material or an increase in the drying step, and the production is based on the use of a high cost and a large amount of a diluent of an environmentally-charged substance. The cost has become very high. Based on this background, review as much as possible to reduce the film thickness of the film and reduce the use of paint. The amount, but the increase in the drying step or the need for the diluent is constant, and the reduction in manufacturing cost is also limited.

As a coated metal plate which does not require a high-cost solvent-based paint, there is a case where a water-based resin paint is used. Since the solvent of the aqueous resin coating is water, it does not consume a large amount of energy due to the increased drying step, and does not use a thinner of a high cost and environmentally hazardous substance, so that the manufacturing cost can be greatly reduced. In the past, it is known that the water-based resin coating film is provided with a water-based resin coating film by special chemical conversion treatment. When the board is painted in black, in order to conceal the surface of the metal sheet, it is necessary to contain a large amount of black pigment in the water-based resin coating film. However, since the black pigment is a component that hinders the film-forming property of the water-based resin coating layer, the corrosion resistance is remarkably lowered, the water-based resin coating layer becomes brittle, and the scratch resistance is remarkably lowered, and the durability of various durability is difficult to be solved. Unevenness, wrinkles, bulges (coating defects that occur when the solvent in the coating is volatilized in a state where a wet film is formed on the surface of the metal sheet or the surface of the coating film), etc., so that it becomes a beautiful water-based resin coating film The layer is difficult. As described above, when a water-based resin coating containing a black pigment is used, it is difficult to achieve improvement in various durability such as improvement in blackness, corrosion resistance, and scratch resistance.

As means for avoiding various durability reductions such as corrosion resistance and scratch resistance, a method of increasing the film thickness of the aqueous resin coating layer is considered. For example, there is a method of simply increasing the film thickness per one layer, a method of further laminating a water-based resin coating film, and the like. In the method of simply increasing the film thickness per layer, there is specifically a solid which improves the composition for forming a water-based resin coating film. The viscosity of the water-based resin coating film forming composition is increased, and the cycle property is lowered, and the production of the high-speed production line becomes difficult, resulting in high cost. Further, as means for avoiding the reduction of the damage resistance, there is also a method of adjusting the silver which is less likely to cause damage. However, in this method, since it is difficult to obtain a beautiful black appearance having a depth, the degree of freedom in design is impaired.

On the other hand, the technique of laminating a metal plate of a water-based resin coating film in which a plurality of water-based resin coating films are laminated is also used in the prior art documents or the chemical conversion processing techniques up to now, not only for black but also for other colors. Almost no. When the composition for forming a water-based resin coating film is applied to the water-based resin coating layer for laminating, it is applied to the resin of the water-repellent organic material, and the viscosity of the composition for forming the aqueous resin coating film is low. It is difficult to apply evenly, and the beautiful finisher is difficult. In addition, when a solvent-based paint is used at the expense of the production cost, the water-based resin coating film is prevented from being laminated in the production (coating) of the PCM based on the reason that the solvent-based resin coating film can be laminated.

Patent Documents 1 to 3 disclose a coated metal sheet of a second layer in which a transparent coating film is laminated on the first layer of the black coating film. However, in these documents, there is no description of a coated metal sheet in which both layers are water-based resin coating layers.

Further, Patent Document 4 discloses a water-based resin coating film laminated metal sheet in which a plurality of water-based resin coating layers are laminated on a metal plate. However, the above-mentioned problems need not be mentioned in the literature, and even the solutions are not touched at all.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2008-23975

[Patent Document 2] JP-A-2011-224972

[Patent Document 3] JP-A-2002-47579

[Patent Document 4] JP-A-2010-22911

An object of the present invention is to provide a water-based resin coating film laminated metal sheet which exhibits beautiful and high blackness. In addition, it is an object of the present invention to provide a water-based resin coating film laminated metal sheet which is particularly excellent in damage resistance in black which is easily damaged.

The first water-based resin coating film laminated metal sheet of the present invention is characterized in that a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and the upper side of the first water-based resin coating layer is A second aqueous resin coating layer containing a transparent coating layer of 3% by mass or more of colloidal cerium oxide.

The second water-based resin coating film laminated metal sheet of the present invention is characterized in that a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and the upper side of the first water-based resin coating layer is a second aqueous resin coating layer containing at least one of a blue pigment or a green pigment and a polyamidamide-based shaker, and a blue pigment and green in the second aqueous resin coating layer The total content of the pigment is 3% by mass or more.

The third water-based resin coating film laminated metal sheet of the present invention is characterized in that a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and the upper side of the first water-based resin coating layer is a second water-based resin coating layer containing at least one of a blue pigment or a green pigment, a colloidal cerium oxide and a polyamine-based rocking agent, and a blue pigment and a green pigment in the second aqueous resin coating layer The content of the colloidal cerium oxide in the second aqueous resin coating layer is 3% by mass or more.

In any of the water-based resin coating film-clad metal sheets, the total thickness of the first water-based resin coating layer and the second water-based resin coating layer is preferably 0.9 to 8.0 μm.

The lightness L* in the L*a*b* color system of the water-based resin coating laminated metal sheet is preferably less than 23.

The black pigment contained in the first water-based resin coating layer is preferably 16% by mass or more and 50% by mass or less, and the black pigment is preferably at least one of ink or carbon black.

The first aqueous resin coating layer preferably contains 25% by mass or more of a polyurethane resin.

The first water-based resin coating film layer is preferably obtained from a first water-based resin coating film-forming composition containing 1% by mass or more of a crosslinking agent.

It is preferable that the second aqueous resin coating film layer does not contain a black pigment.

The second aqueous resin coating layer preferably contains 25% by mass or more of a polyethylene resin, and the first aqueous resin coating layer preferably has a film thickness. The film thickness of the second aqueous resin coating layer is not more than 4 times.

The above metal plate is preferably an electrogalvanized metal plate.

According to the present invention, it is possible to provide a water-based resin coating laminated metal sheet which exhibits beautiful and high blackness. The water-based resin coating film laminated metal sheet of the present invention can be manufactured without using a solvent having a high environmental load or a solvent-based resin which requires a large amount of energy during drying, so that the process cost can be greatly reduced. Therefore, the beautiful and black water-based resin coating laminated metal sheet of the present invention which is manufactured at low cost can be used for a casing or interior of an automobile or home electric appliance, ‧ exterior parts, steel furniture, and the like Materials, etc.

FIG. 1 shows the relationship between the black pigment concentration of the first aqueous resin coating layer and the L* of the water-based resin coating laminated metal sheet when the second aqueous resin coating layer is a clear coating layer.

[Formation of the Invention]

As a method of imparting a high degree of blackness to a metal plate, for example, it is considered that a water-based resin coating film layer which is formed by laminating two layers of a water-based resin coating film layer on a metal plate is appropriately adjusted (hereinafter referred to as a first water-based resin coating film layer). The concentration of the black pigment in the water-based resin coating film, and the water-based resin coating layer on the first water-based resin coating layer (hereinafter referred to as the second water-based resin coating) The film layer is a transparent water-based resin coating film layer. In order to increase the blackness by adjusting the concentration of the black pigment in the first aqueous resin coating layer, it is necessary to absorb the black pigment in the aqueous resin coating film as much as possible without reflecting the light. When the concentration of the black pigment is too low, the amount of light reflected from the gap between the black pigments is increased, and a sufficient degree of blackness cannot be obtained. Further, the aqueous resin coating layer is a coating layer obtained by dispersing an aqueous dispersion of a resin in an aqueous medium, and means that the surfactant remains in the coating film due to water dispersion of the resin by the surfactant. A coating layer formed in a layer or a coating layer formed of a water-dispersible resin containing a highly hydrophilic carboxylic acid or sulfonic acid in a resin skeleton, or a coating layer coexisting therewith.

On the other hand, when the concentration of the black pigment in the first water-based resin coating layer is appropriately adjusted, in order to make the black pigments less likely to aggregate with each other, for example, a surface coated with a black pigment with a resin or a surfactant is used, and black is applied. The primary particle diameter of the pigment is adjusted to an average of about 0.2 μm. However, even if the concentration in the aqueous resin coating film is high and the distance between the black pigments is too close, it is difficult to avoid aggregation, and the aggregate secondary particles are increased, and the gaps are transmitted from the gaps of the black pigments. ‧The reflected light system is increased, making it difficult to absorb light with black pigment. In the case where the first water-based resin coating layer containing ink or carbon black has a thickness of 1 μm and the second water-based resin coating layer of the transparent water-based tree coating layer has a thickness of 1 μm, the first aqueous resin is used. The relationship between the black pigment concentration of the coating layer and the L* of the water-based resin coating laminated metal sheet (the lower the L*, the higher the blackness). In the concentration of about 30% by mass of the ink and carbon black, L* becomes the lowest (L*=23), and the blackness becomes the largest. However, the water-based resin coating film of L*≧23 is laminated with gold. In the slab, the bottom plate cannot be completely concealed, and it is difficult to say that it is beautiful black in the visual appearance.

When the blackness is further increased and the pattern design property is to be excellent, the black pigment is also considered not only in the first water-based resin coating layer but also in the second water-based resin coating layer. However, it is understood that when the black second resin coating layer is further laminated on the first water-based resin coating layer in which the blackness is maximized (L* is the smallest), the L* is increased and the blackness is lowered. . It is considered that the black pigment of the second water-based resin coating layer hinders the light absorption of the first water-based resin coating layer.

Based on the above, the inventors of the present invention reflect the light on the surface of the colloidal ceria or the colored pigment having a refractive index different from that of the resin component of the second aqueous resin coating layer, and the first aqueous resin coating layer is applied. The light that has not been absorbed by the black pigment is returned to the first water-based resin coating layer, and the black pigment of the first water-based resin coating layer absorbs light, thereby achieving the idea of improving the blackness. In other words, the present invention has been conceived by adding an additive which can increase the degree of blackness such as colloidal ceria, cyanine blue or cyan in the second aqueous resin coating layer.

In the water-based resin coating film laminated metal sheet of the present invention, a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and a layer of the second water-based resin coating layer is laminated on the side of the first water-based resin coating layer. A second aqueous resin coating layer of at least one of cerium oxide, a blue pigment, and a green pigment.

Hereinafter, a constituent material and a production method of the water-based resin coating film laminated metal sheet in the present invention will be described.

[Metal plate]

The metal plate in which the coating film is laminated is not particularly limited as long as it is a user of the bottom plate which is a precoated metal. For example, a metal plate such as an electrogalvanized metal plate (EG), a non-plated cold-rolled metal plate, a hot-dip galvanized metal plate (GI), an alloyed hot-dip galvanized metal plate (GA), and an aluminum plate and a titanium plate may be mentioned. Wait. Among these, electroplated zinc metal plate (EG), hot-dip galvanized metal plate (GI), aluminum plate and titanium plate are preferable, and electrogalvanized metal plate (EG) is more preferable. This is because the electro-galvanized metal plate (EG) is suitable for electronic and electrical parts such as the back cover of a thin TV.

The metal plate is preferably formed on the at least one side by a pre-substrate treatment to form the underlayer. For example, when the chemical conversion film layer (base layer) formed by the base treatment is provided on the surface of the metal plate on the side where the first aqueous resin coating film layer is formed, the adhesion between the metal plate and the first aqueous resin coating film layer is increased.

Examples of the chemical conversion coating layer (base layer) include an organic coating layer, an inorganic coating layer, a phosphate coating layer, and a chromate coating layer. As the organic film layer, for example, a polyethylene resin, an epoxy resin, an acrylic resin, a urethane resin, a polyester resin, a fluorine resin, a mixture, a copolymer, or the like can be suitably selected. It is used as a resin or the like. In the organic film, for the purpose of improving the corrosion resistance, a ruthenium gel or a colloidal ruthenium dioxide may be further added, and for the purpose of improving the workability after the application of the coating film, a small amount of various wax components or a coating film may be added. For the purpose of improving the adhesion, a decane coupling agent may be added. Examples of the inorganic coating layer include a bismuth citrate coating layer, and phosphoric acid or a fluoride may be added to the bismuth citrate coating. The phosphate coating layer is one or more selected from the group consisting of Mg, Al, Co, Mn, and Ca. A phosphate layer composed of a metal as a main component film layer.

For the purpose of improving the adhesion to the resin film or the corrosion resistance, it is preferred to apply a phosphate film layer to the metal plate as a base layer.

The amount of adhesion of the chemical conversion film layer (base layer) is not particularly limited. However, when it is an organic film layer or an inorganic film layer, it is preferably 50 mg/m ² or more in terms of dryness from the viewpoint of corrosion resistance. However, if it exceeds 150 mg/m ² , the improvement effect of corrosion resistance is saturated, and the manufacturing cost increases.

As a metal plate on which the underlayer is formed, a particularly preferable aspect is, for example, coating a substrate treatment composition containing aluminum dihydrogen phosphate, colloidal cerium oxide, and polyacrylic acid (hereinafter also referred to as "specific substrate treatment composition"). Dry on a galvanized metal plate. If the specific substrate treatment composition is coated on a galvanized metal plate, the surface of the metal plate is etched by hydrogen ions from aluminum dihydrogen phosphate while being passed through aluminum ions and colloidal particles from aluminum dihydrogen phosphate. By the interaction of cerium oxide, a poorly soluble film having excellent adhesion to the first water-based resin coating layer can be formed, and as a result, the film adhesion after bending or press working (elongation/contraction deformation) can be improved, and corrosion resistance or corrosion resistance can be obtained. The tape peeling resistance is greatly improved.

In the specific substrate treatment composition, the ratio of the content of the aluminum dihydrogen phosphate to the colloidal cerium oxide is preferably aluminum dihydrogen phosphate: colloidal cerium oxide (mass ratio) = 30:70 to 70:30. More preferably 35:65~65:35, especially good 40:50~60:50). When the amount of the colloidal cerium oxide is more than the above ratio, the film forming property is lowered and it is difficult to form the underlayer, and it is difficult to obtain the effect of improving corrosion resistance or adhesion to the overcoat layer, and further, the adhesion to the metal plate is difficult. The contactability is also low, and there is a flaw in the peeling of the coating film after processing. On the other hand, if the amount of colloidal cerium oxide is less than the above ratio, since the proportion of aluminum dihydrogen phosphate increases, the proportion of residual aluminum dihydrogen phosphate which is not reacted (etched) with the metal plate is increased in water, under the coating film. Corrosion occurs and corrosion resistance decreases.

The specific base treatment composition is preferably contained in an amount of 1.0 to 10.0 parts by mass (more preferably 3.0 parts by mass or more and 6.0 parts by mass or less) based on 100 parts by mass of the total solid content of the aluminum dihydrogen phosphate and the colloidal cerium oxide. Polyacrylic acid. It is considered that the polyacrylic acid has an effect of appropriately controlling the reaction (etching) of the surface (zinc plating) of the metal plate to which zinc plating or the like is applied, and aluminum dihydrogen phosphate. If the amount is less than the above range, the etching excessively occurs, and as a result, the result is excessive. When the corrosion resistance is lowered, if the amount is more than the above range, the etching is insufficient, and the poorly soluble film system produced by the aluminum dihydrogen phosphate and the colloidal cerium oxide is insufficiently formed, and it is difficult to obtain adhesion and corrosion resistance. Improve the effect.

The specific base treatment composition is preferably contained in an amount of from 3 to 15 parts by mass, more preferably from 5 parts by mass to 12.5 parts by mass, per 100 parts by mass of the total solid content of the aluminum dihydrogen phosphate and the colloidal cerium oxide. Decane coupling agent. When the amount of the decane coupling agent is less than the above range, the effect of improving the adhesion between the top coat layer and the metal sheet or the corrosion resistance tends to be insufficient, and the peeling of the film may occur under more severe processing conditions. On the contrary, if it is more than the above range, there is still a fear that the corrosion resistance or the adhesion is lowered.

[First water-based resin coating layer] <carbon black>

The first aqueous resin coating layer contains a black pigment. The black pigment is preferably at least one of ink or carbon black.

Carbon black is recommended, for example, "SA Black DY-6" manufactured by Yuki Co., Ltd., "#4000B" manufactured by Mitsubishi Chemical Corporation, "#4350B", "MHIB #B239M", "MHIB #B240M", and the like.

The ink is surface-treated carbon black coated on the surface of the water-based resin, and for example, a high-concentration ink droplet (ink) used for calligraphy is preferably used. When the ink is mixed with the binder resin, the ink exhibits excellent dispersibility, and the second aqueous resin coating layer can exhibit a high degree of blackness even if it is a thin film thickness as will be described later. The ink droplets are aqueous dispersions containing surface-treated carbon black, for example, a surface of an amorphous furnace black which is produced by a furnace method in which a petroleum-based or coal-based oil is incompletely burned in a high-temperature gas by coating with a water-based resin. A glycol-based antifreeze and a preservative are added as needed, and they are mixed and refined. As the ink droplets, for example, commercially available inks (for example, "Super Concentrated Ink Drops BA-8" manufactured by K.K.) can be used. In addition, the surface-treated carbon black or the aqueous dispersion thereof can also be prepared according to a known method (for example, JP-A-7-188597 or JP-A-6-234946). The surface-treated carbon black (or its aqueous dispersion) may be used singly or in combination of two or more.

The black pigment is preferably contained in an amount of 16% by mass or more and 50% by mass or less, more preferably 25% by mass or more and 45% by mass or less, based on 100% by mass of the total solid content of the first water-based resin coating layer-forming composition. When the content of the black pigment is less than 16% by mass, the L* value of the water-based resin coating laminated metal sheet becomes high because it does not contain a sufficient amount of black pigment. Now full of blackness. On the other hand, when the content of the black pigment is more than 50% by mass, the resin component as a binder contained in the composition is relatively reduced, and the first aqueous resin coating layer and the second aqueous resin coating layer are in close contact with each other. When the properties are low, the composition is liable to gel, and the liquid stability of the first water-based resin coating layer-forming composition is lowered. When the content of the black pigment is 16% by mass or more and 50% by mass or less, even if the black pigment is mixed with the binder resin, secondary aggregation is difficult, and high dispersion stability can be maintained.

<Binder Resin>

The composition for forming a water-based resin coating film for coating a first water-based resin coating film layer (hereinafter referred to as a first water-based resin coating film-forming composition) usually includes a black pigment fixed to the composition. A binder resin used in the first water-based resin coating layer. The type of the binder is not particularly limited as long as the black pigment can be fixed, and an acrylic resin, a urethane resin, a polyolefin resin, a polyester resin, a fluorine resin, or a hydrazine can be suitably used. An oxygen-based resin and a resin mixed or modified with the same. Among them, a polyethylene resin or a polyurethane resin is preferable because it can effectively suppress secondary aggregation of the black pigment in the composition and obtain excellent liquid stability. The binder resin may be used singly or in combination of two or more.

In the total solid content of 100% by mass of the first water-based resin coating film-forming composition, the binder resin is preferably 30% by mass or more (more preferably 35% by mass or more) and 70% by mass or less (more preferably 65% by mass). % below) Have. When the content of the binder resin is less than 30% by mass, the film forming property of the first water-based resin coating layer is lowered, and the fixing of the black pigment in the first water-based resin coating layer is insufficient, and coating unevenness occurs. Incurs the problem of appearance. On the other hand, when the content of the binder resin exceeds 70% by mass, the content of the relatively black pigment decreases, and sufficient blackness cannot be obtained.

Moreover, in order to make the first water-based resin coating layer tough, the polyurethane resin is preferably contained in an amount of 25% by mass or more (more preferably 35% by mass or more), and the polyurethane resin is more preferable. It is a carboxyl group-containing polyurethane resin. By containing a polyurethane resin, the first water-based resin coating layer can be made tough, and the first aqueous resin coating layer contains 25% by mass or more of a polyurethane resin. A water-based resin coating film laminated metal sheet excellent in scratch resistance is obtained.

The carboxyl group-containing polyurethane resin is obtained by chain extension reaction of a urethane prepolymer with a chain extender, and the urethane prepolymer is a polyisocyanate component described later. It is obtained by reacting with a polyol component. The polyisocyanate component constituting the above urethane prepolymer is preferably composed of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and dicyclohexylmethane diisocyanate (hydrogenated MDI). At least one polyisocyanate selected from the group. By using the polyisocyanate, a resin film excellent in corrosion resistance and stability in reaction control can be obtained. In addition to the above-mentioned suitable polyisocyanate, other polyisocyanates may be used insofar as the corrosion resistance or the stability controlled by the reaction is not lowered, but the content of a suitable polyisocyanate component is preferably the total polyisocyanate component. 70% by mass or more. When the content ratio of a suitable polyisocyanate component is less than 70% by mass, the corrosion resistance ‧ the stability of the reaction control tends to be lowered. Examples of the polyisocyanate other than the above-mentioned suitable polyisocyanate component include tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, and xylene diisocyanate. Phenyl diisocyanate and the like. The polyisocyanate may be used singly or in combination of at least two kinds.

As the polyol component constituting the urethane prepolymer, it is preferred to use all of the three types of polyols of 1,4-cyclohexanedimethanol, a polyether polyol, and a carboxyl group-containing polyol. All three types are diols. By using this polyol component, a resin film excellent in corrosion resistance or slidability can be obtained. Further, as the polyol component, the rust preventing effect of the obtained polyurethane resin can be improved by using 1,4-cyclohexanedimethanol.

The polyether polyol is not particularly limited as long as it has at least two or more hydroxyl groups in the molecular chain and the main skeleton is composed of alkylene oxide units, and examples thereof include polyoxyethylene glycol (also referred to as polyoxyethylene glycol). "Polyethylene glycol", polyoxypropylene glycol (also known as "polypropylene glycol"), polyoxytetramethylene glycol (also known as "polytetramethylene glycol" or " A commercially available person can be used, for example, in the case of polytetramethylene ether glycol. Among the above polyether polyols, polyoxypropylene glycol or polytetramethylene ether glycol is preferably used. The number of functional groups of the polyether polyol is not particularly limited as long as it is at least 2, and may be, for example, a trifunctional or tetrafunctional or higher polyfunctional group.

The above polyether polyol can be used, for example, as a compound having active hydrogen The starting agent is obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide. Examples of the active hydrogen-containing compound include a diol such as propylene glycol or ethylene glycol, a triol such as glycerin, trimethylolpropane, hexanetriol or triethanolamine, diglycerol or pentaerythritol. And sorbitol, sucrose, phosphoric acid, and the like. In this case, when a diol is used as a starting agent to be used, a bifunctional polyether polyol is obtained, and when a triol is used, a trifunctional polyether polyol is obtained.

Further, the polyoxytetramethylene glycol can be obtained, for example, by ring-opening polymerization of tetrahydrofuran.

The polyether polyol is preferably, for example, a commercially available one having an average molecular weight of about 400 to 4,000. This is because if the average molecular weight is less than about 400, the resin film is hard, and if it exceeds 4,000, it is too soft. Further, the average molecular weight is determined from the OH value (hydroxyl value) of the polyol.

In the present invention, it is also preferred that the mass ratio of the above 1,4-cyclohexanedimethanol to the polyether polyol is 1,4-cyclohexanedimethanol: polyether polyol = 1: 1~1:19. This is because the rust-preventing effect of the obtained polyurethane resin can be further improved by using a certain ratio of 1,4-cyclohexanedimethanol having a rust preventive effect.

The carboxy group-containing polyol to be used in the invention is not particularly limited as long as it has at least one or more carboxyl groups and at least two or more hydroxyl groups, and examples thereof include dimethylolpropionic acid and dimethylol group. Butyric acid, dihydroxypropionic acid, dihydroxysuccinic acid, and the like.

In addition to the above-mentioned suitable polyol component, other polyols may be used insofar as the corrosion resistance is not lowered, but a suitable polyol component is contained. The yield is preferably 70% by mass or more of all the polyol components. In this case, if the content ratio of a suitable polyol component is less than 70% by mass, the corrosion resistance tends to be lowered. The polyol other than the above-mentioned suitable polyol component is not particularly limited as long as it has a plural number of hydroxyl groups, and examples thereof include a low molecular weight polyol or a high molecular weight polyol. The low molecular weight polyol is a polyhydric alcohol having a molecular weight of about 500 or less, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butylene glycol, and 1,4-butanediol. a diol such as pentanediol or 1,6-hexanediol; a triol such as glycerin, trimethylolpropane or hexanetriol.

The high molecular weight polyol is a polyol having a molecular weight of more than about 500, and examples thereof include polyethylidene adipate (PEA), polybutylene adipate (PBA), and polyhexamethylene adipate. a condensation polyester polyol such as ester (PHMA); a lactone polyester polyol such as poly-ε-caprolactone (PCL); a polycarbonate polyol such as polyhexamethylene carbonate; Acrylic polyol and the like.

In addition, the chain extender which reacts the urethane prepolymer to the chain extension reaction is not particularly limited, and examples thereof include a polyamine, a low molecular weight polyol, and an alkanolamine. The low molecular weight polyol may be the same as the above, and examples of the polyamine include aliphatic polyamines such as ethylenediamine, propylenediamine and hexamethylenediamine; toluenediamine and benzene. An aromatic polyamine such as methyl diamine or diaminodiphenylmethane; diaminocyclohexylmethane, piperazine An alicyclic polyamine such as isophorone diamine; an anthracene such as hydrazine, diterpene succinate, diammonium adipate or diterpene phthalate. Among these, it is preferred to use ethylenediamine and/or hydrazine as a chain extender component. Further, examples of the alkanolamine include diethanolamine and monoethanolamine.

In the present invention, a preferred embodiment is an aqueous dispersion using the above carboxyl group-containing polyurethane resin. The aqueous dispersion of the above carboxyl group-containing polyurethane resin can be produced by a well-known method, for example, by neutralizing the carboxyl group of the carboxyl group-containing urethane prepolymer with a base in water. The method of emulsifying and dispersing, and extending the chain, in the presence of an emulsifier, emulsification and dispersion of a carboxyl group-containing polyurethane resin by high shear force, and a chain extension reaction method, etc., may also be A known method (for example, JP-A-2005-199673) is produced. In addition, when the polyurethane resin coating layer is contained in the second water-based resin coating layer, it can be adjusted in the same manner as described above.

<colloidal cerium oxide>

The first aqueous resin coating layer preferably contains 5% by mass or more of colloidal cerium oxide, more preferably 7% by mass or more and 40% by mass or less, and particularly preferably 10% by mass or more and 30% by mass or less. By containing colloidal cerium oxide, corrosion resistance can be imparted, and since it is hard particles, the damage resistance of the first water-based resin coating layer at the time of processing can be improved. When the content of the colloidal cerium oxide is less than 5% by mass, the corrosion resistance is lowered. In addition, when the content of the colloidal cerium oxide is more than 40% by mass, the film-forming property of the aqueous resin coating film is lowered, the corrosion resistance is lowered, or the film is brittle and the workability is deteriorated.

The colloidal cerium oxide is not particularly limited, but is preferably a colloid having a particle diameter of 1 to 20 nm from the viewpoint of the dispersibility or the effect of improving the corrosion resistance of the first aqueous resin coating film-forming composition. Ceria, Specifically, a colloidal ceria having a particle diameter of 4 to 6 nm (a "Snowtex (registered trademark) XS" manufactured by Nissan Chemical Co., Ltd.) and a colloidal ceria having a particle diameter of 8 to 11 nm are commercially available. "Snowtex (registered trademark) S" manufactured by Nissan Chemical Co., Ltd., and colloidal cerium oxide having a particle size of 10 to 20 nm (commercial product "Snowtex (registered trademark) 40" manufactured by Nissan Chemical Co., Ltd.), etc. Among them, Teka is "Snowtex (registered trademark) XS".

Further, in order to maximize the effect of the colloidal cerium oxide, the average particle diameter of the colloidal cerium oxide is preferably in the range of 3 to 15 nm. This is because the smaller the average particle size of the colloidal cerium oxide, the higher the corrosion resistance of the aqueous resin coating film, but if the average particle diameter is less than about 3 nm, the effect of improving the corrosion resistance tends to be saturated, and the first water system The stability of the composition for forming a resin coating film is lowered, and it is easy to gel. On the other hand, when the average particle diameter of the colloidal cerium oxide exceeds 15 nm, the film forming property of the first aqueous resin coating film is lowered, and the corrosion resistance tends to be deteriorated.

Further, the average particle diameter of the colloidal cerium oxide and other powders can be determined from the value of the specific surface area measured by the BET adsorption method in accordance with JIS Z8830-2013. The method of calculating the particle diameter from the specific surface area of the microparticles is shown below.

The specific surface area S (m ² /g) of the microparticles is the sum of the surface areas of the 1 g portion of the microparticles. That is, the specific surface area S (m ² /g) of the fine particles is a value obtained by dividing the surface area of one fine particle by the mass of one fine particle. Assuming that the microparticles are truly spherical and have no pores, the surface area of the microparticles is 4π(d/2) ² = πd ² (nm ² ), and the mass of one microparticle is ρ‧{4π/3×(d ^{/ 2) 3} = ρ‧πd 3} /6 (nm 3 × g / cm 3) ( particle diameter of fine particles is d (nm), a density ^{ρ (g / cm 3))} . Then, the specific surface area S (m ² /g) of the fine particles can be expressed by the following formula.

S(m ² /g)= π d ² (nm ² )/( ρ ‧ π d ³ /6)(nm ³ ×g/cm ³ )=6/d‧ ρ ((nm ² )/(nm ³ × g/cm ³ )) = 6,000 / d ‧ ρ (m ² /g) Therefore, since d (nm) = 6,000 / S ‧ ρ, the particle diameter can be determined from the specific surface area.

<decane coupling agent>

The composition for forming the first aqueous resin coating film may further contain a decane coupling agent. When the decane coupling agent is contained, the adhesion between the first aqueous resin coating layer and the metal plate can be improved.

The decane coupling agent is preferably a decane coupling agent having a glycidoxy group at the terminal, and examples thereof include γ-glycidoxypropyltrimethoxydecane and γ-glycidoxypropylmethyl. Diethoxydecane, vinyl tris(β-methoxyethoxy)decane, and the like.

The content of the decane coupling agent is preferably 5 parts by mass or more (more preferably 10 parts by mass or more), more preferably 25 parts by mass based on 100 parts by mass of the total of the black pigment, the binder resin, and the colloidal cerium oxide. The mass part is below (more preferably 15 parts by mass or less). When the content of the decane coupling agent is less than 5 parts by mass, the effect obtained by adding a decane coupling agent may not be sufficiently obtained. On the other hand, when the content of the decane coupling agent exceeds 25 parts by mass, the unreacted decane coupling agent remains in the water-based resin coating film laminated metal sheet, and the corrosion resistance tends to be lowered.

<crosslinker>

In the first water-based resin coating film-forming composition, the crosslinking agent is preferably contained in an amount of 1% by mass or more. When the crosslinking agent is contained in an amount of 1% by mass or more, the first aqueous resin coating layer is made tough, and the scratch resistance can be further improved. Examples of the crosslinking agent include an epoxy compound, a melamine compound, and an isocyanate compound.

<film thickness>

The film thickness (dry film thickness) of the first water-based resin coating layer is preferably 0.6 μm or more (more preferably 0.9 μm or more, and particularly preferably 1.1 μm or more) of 7.0 μm or less (more preferably 6.0 μm or less, and particularly preferably 5.0μm or less). When the film thickness of the first water-based resin coating layer is less than 0.6 μm, when the polyurethane resin is contained in the first water-based resin coating layer, it is toughened by the inclusion of the polyurethane resin. The coating film, but there is not enough damage resistance. On the other hand, when the film thickness of the first water-based resin coating layer exceeds 7.0 μm, wrinkles are likely to occur in the first water-based resin coating layer, and the appearance is liable to be defective. Moreover, the time taken for painting or drying becomes long, and the manufacturing cost increases.

<Other>

The first aqueous resin coating layer preferably contains a polyamine-based shaker. The details are as follows.

[Second water resin coating layer] <pigment>

In the second water-based resin coating layer, one or two or more selected from the group consisting of colloidal cerium oxide, blue pigment, and green pigment are contained. The second aqueous resin coating layer may be a gelatinous cerium oxide, but may not contain a blue pigment or a green pigment, or may be at least one of a blue pigment or a green pigment, but does not contain colloidal cerium oxide. . The colloidal cerium oxide is transparent and hard to absorb light, and the blue pigment or the green pigment absorbs specific light, but has no high absorbability as a black pigment, so that the blackness improving effect is easily obtained.

From the viewpoint of the effect of improving the blackness, the colloidal cerium oxide is preferably a fine particle having an average particle diameter of 1 to 100 nm. Further, the upper limit of the average particle diameter of the colloidal ceria is 50 nm, and the upper limit is preferably 25 nm, and the lower limit is 4 nm.

As a method of measuring the average particle diameter of the colloidal cerium oxide, in addition to the BET method described above, a Sears method, a dynamic light scattering method, or the like may be used. For example, when the average particle diameter is 4 to 6 nm, it is preferably According to the Schirns method, when the average particle diameter is 10 to 100 nm, the BET method is preferably used, and in the case of chain cerium oxide, the dynamic light scattering method is preferably used.

In addition, the content of the black pigment in the second aqueous resin coating layer is preferably 10% by mass or less, and more preferably is not contained. When the black pigment is added to the second water-based resin coating layer, the black pigment is added to the second water-based resin coating layer, and the damage resistance of the second water-based resin coating layer is lowered.

<colloidal cerium oxide>

By containing colloidal cerium oxide in the second aqueous resin coating layer, the corrosion resistance or hardness of the obtained water-based resin coating laminated metal sheet can be improved. Although the details of the mechanism for improving the corrosion resistance are not known, it is presumed that the cerium dioxide is dissolved and eluted in a corrosive environment, and a pH buffering action or a passive film forming action occurs.

Further, the colloidal cerium oxide system has an effect of improving the blackness comparable to the blue pigment described later, and the effect of improving the blackness is larger than that of the green pigment described later. The refractive index of colloidal cerium oxide and blue pigment ‧ green pigment is about 1.5 without difference, but the average particle size of colloidal cerium oxide is generally smaller than the average particle diameter of blue pigment and green pigment, due to In comparison with the coloring pigment, the interface area with the resin is increased. Therefore, by including the colloidal cerium oxide in the second aqueous resin coating layer, it is judged that the blackness improving effect comparable to the blue pigment can be obtained.

The colloidal cerium oxide is not particularly limited, and may be the same type as the colloidal cerium oxide used in the composition for forming a first aqueous resin coating film.

In the 100% by mass of the total solid content of the water-based resin coating film-forming composition (hereinafter referred to as the second water-based resin coating film-forming composition) used for the coating of the second water-based resin coating layer, colloidal cerium oxide ( The solid content is preferably 3% by mass or more (more preferably 10% by mass or more), and is preferably 70% by mass or less (more preferably 60% by mass or less). When the content of the colloidal cerium oxide is less than 3% by mass, the blackness (L* value) of the water-based resin coating laminated metal sheet is 23 or more, and it is difficult to say that it is beautiful black in visual appearance, and corrosion resistance is also lowered. . On the other hand, the content of colloidal cerium oxide When the rate exceeds 70% by mass, the stability of the composition is deteriorated, and the viscosity is increased as time passes, and the effect of further improving the corrosion resistance is not obtained, which is economically disadvantageous.

<Blue pigment ‧ green pigment>

When the second water-based resin coating layer does not contain colloidal cerium oxide, it is necessary to contain at least one of a blue pigment or a green pigment and a polyamine-based rocking agent in the second aqueous resin coating layer. The total content of the blue pigment and the green pigment in the second water-based resin coating layer is 3% by mass or more, preferably 5% by mass or more, and more preferably 10% by mass or more. When the total content of the blue pigment and the green pigment is less than 3% by mass, it is difficult to obtain a sufficient degree of blackness in the water-based resin coating laminated metal sheet. On the other hand, the coloring pigment is a component that hinders the film forming property, and there is a possibility that the adhesion is lowered. Therefore, in order to sufficiently ensure the adhesion between the second water-based resin coating layer and the first water-based resin coating layer, the total content of the blue pigment and the green pigment in the second water-based resin coating layer is preferably 80% by mass or less. More preferably, it is 70% by mass or less, and particularly preferably 50% by mass or less.

In addition, at least one of a blue pigment or a green pigment and a polyamine-based shaker may be contained in the second aqueous resin coating layer in a state containing colloidal cerium oxide. The details of the polyamine-based shaker are as follows.

As a blue pigment, "AF Blue E-2B" (made by Dairi Seiki Co., Ltd.), which is made of phthalocyanine pigment and water-soluble acrylic resin, and phthalocyanine pigment and "SA Blue DY-12" (made by Yuki Co., Ltd.) made of water-soluble styrene acrylic resin, from cyanine pigments and non- "PSM Blue HB" (manufactured by Yuki Co., Ltd.) made of an ion-based surfactant, etc., among them, "SA Blue DY-12".

As a green pigment, "AF Green E-1" (made by Dairi Seiki Co., Ltd.) made of phthalocyanine-based pigment and water-soluble acrylic resin, and phthalocyanine pigment and water-soluble are used in the commercial product. "SA Green DY-4" (made by Yuki Co., Ltd.) made of a styrene-acrylic resin, etc., among them, "SA Green DY-4" is especially preferable.

The blue pigment and the green pigment are preferably phthalocyanine pigments. Moreover, the blue pigment can increase the blackness more than the green pigment. It is judged that the blue color is darker than the green color, and the effect of increasing the blackness is large.

<Polyamide-based shaker>

As described above, in the present invention, when the blue water-based resin coating film layer contains a blue pigment or a green pigment, a polyamine-based rocking agent is also added to the second water-based resin coating film-forming composition. When the second water-based resin coating layer such as a blue pigment or a green pigment is laminated on the first water-based resin coating layer, the blackness of the water-based resin coating laminated metal sheet is increased, but on the other hand, 2 The coating of the water-based resin coating layer is not conspicuous. Specifically, in the coating of the aqueous resin coating film, since the components such as the pigment are present on the surface of the wet film, the wettability is deviated, and irregularities are formed on the surface of the aqueous resin coating film. Uneven cloth. When the second aqueous resin coating layer does not contain a blue pigment or a green pigment, and only the colloidal cerium oxide is contained, since the colloidal cerium oxide is fine particles and is transparent, the second aqueous resin coating layer is not colored, even in the case of Table of the second water-based resin coating layer Concavities and convexities appear on the surface, and uneven coating is not conspicuous. However, when at least one of a blue pigment or a green pigment is contained, since these pigments are coloring pigments, coating unevenness is conspicuous. In order to suppress coating unevenness of such a second water-based resin coating layer, a polyamine-based shaker is added to the second aqueous resin coating layer. Further, when the second aqueous resin coating layer does not contain a blue pigment or a green pigment, and only the colloidal cerium oxide is contained, a polyamine-based shaker may be added.

When at least one of the blue pigment or the green pigment is contained in the second water-based resin coating layer, the polyamine-based shaker is contained in an amount of 0.05% by mass or more, more preferably 0.1% by mass to 5% by mass. The solid content of the treatment liquid is also affected, and the viscosity of the low-shearing speed range of the composition for forming the second aqueous resin coating film can be sufficiently increased even if the polyamine-based shaker is a small amount of about 0.05% by mass. Since the uniform wet film can be maintained in a uniform state immediately after coating until after drying, uneven coating can be effectively prevented. In this way, the second aqueous resin coating layer containing at least one of the blue pigment and the green pigment can be uniformly applied onto the first aqueous resin coating layer of the black layer to form a water system having a beautiful appearance. The resin coating film is laminated with a metal plate. When the polyamine-based shaker is less than 0.05% by mass, the viscosity in the low shear rate range of the second aqueous resin coating film-forming composition is not sufficiently increased, and a uniform wet film is maintained immediately after coating. It becomes difficult in a uniform state until it is dried.

The polyamine-based shaker is obtained by reacting a dicarboxylic acid with a diamine, but it is not particularly limited as long as it is a polyamine-based shaker which can be dispersed in the composition for forming a second aqueous resin coating film. limited. As a polyamine-based shaker, an example For example, in the Disparlon (registered trademark) AQ series, it can be obtained from Nanben Chemical Company. In the AQ series, polyamine which is represented by the following chemical formula (R, R' is an alkyl group) is used as a main component, and the molecular weight of the polyamine in the AQ series is 3,000 or less.

It is considered that a polyamine-based shaker is formed by forming a three-dimensional mesh structure in a coating material, and producing a pigment such as a resin or a cerium dioxide particle, a coloring pigment, or the like in a coating of a polyamide-based rocking agent. The steric obstacle or the steric obstacle of the particles is increased by the adsorption, and the fluidity suppressing effect of the second aqueous resin coating film-forming composition is exhibited. Since this mesh structure is composed of weak bonds such as van der Waals force or hydrogen bonding, it can be easily cut at a certain degree of shear speed, but if it is left, the mesh structure is restored. Therefore, by adding a polyamine-based shaker to the second water-based resin coating film-forming composition, thixotropy is exhibited, and the mesh structure is cut in a high shear rate range, and the viscosity is lowered. When it is set to a low shear speed range, the mesh structure is restored and the viscosity is increased.

Further, as described above, in the first aqueous resin coating layer, a polyamine-based shaker is preferably added. In the first water-based resin coating layer, the polyamine-based rocking agent is preferably contained in an amount of 0.05 to 5% by mass, more preferably 0.1% by mass. The above 2% by mass or less. By increasing the viscosity of the composition for forming the first aqueous resin coating film in the low shear rate range, the first aqueous resin coating layer can be more reliably maintained in a uniform state until after drying. In addition, the pigment moves in the first water-based resin coating layer, and as a result, segregation of the pigment is prevented, and the unevenness of the surface of the first water-based resin coating layer (the surface in contact with the second aqueous resin coating layer) is suppressed as much as possible. Since the difference in film thickness is reduced, the influence on the second aqueous resin coating layer is small, and occurrence of uneven coating can be suppressed.

<Lubricant>

The second aqueous resin coating layer preferably contains a lubricant. By containing a lubricant, the friction on the surface of the second aqueous resin coating layer is reduced, and damage is less likely to occur. The lubricant is preferably contained in an amount of 1.5% by mass or more, more preferably 3.0% by mass or more and 20% by mass or less. When the content of the lubricant is less than 1.5% by mass, the lubricity of the obtained second aqueous resin coating layer is not sufficiently improved, and the friction reducing effect is insufficiently obtained. Even if a lubricant of more than 20% by mass is added, the effect of lowering the coefficient of dynamic friction is saturated and wastes.

As the lubricant, polyolefin-based waxes such as polyethylene, oxidized polyethylene, and polypropylene; fluorine-based resins such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and tetrafluoroethylene; and organic modification can be used. Polyoxane; paraffin, etc. Among these, polyethylene wax or organically modified polyoxyalkylene is preferred.

The polyethylene wax is spherical in the second water-based resin coating layer, and the friction on the surface of the second water-based resin coating layer can be effectively reduced. Inhibition of the occurrence of damage, etc. Examples of the polyethylene wax include "Chemipearl (registered trademark) W700", "Chemipearl (registered trademark) W950", "Chemipearl (registered trademark) W900" manufactured by Mitsui Chemicals, Inc., and the like. The amount of the polyethylene wax added is preferably 1.5% by mass or more, and more preferably 3.0% by mass or more. When the content of the polyethylene wax is less than 1.5% by mass, the lubricity of the obtained second aqueous resin coating layer is not sufficiently improved, and the friction reducing effect is insufficiently obtained. When the content of the polyethylene wax is more than 20% by mass, the film forming property of the second water-based resin coating layer is lowered, and the corrosion resistance is lowered.

As the polyethylene wax particles, those having a spherical shape and having an average particle diameter of 0.1 to 3 μm are preferably used. When the average particle diameter is more than 3 μm, it is difficult to uniformly disperse the second water-based resin coating film-forming composition, and the corrosion resistance tends to be lowered due to the formation of the film-forming property. On the other hand, when the average particle diameter of the polyethylene wax particles is smaller than 0.1 μm, the lubricity of the second water-based resin coating layer does not increase. Further, the average particle diameter of the polyethylene wax particles can be measured by a Coulter counting method.

The organic modified polyoxyalkylene can effectively reduce the friction of the surface of the second aqueous resin coating layer by floating the surface of the second aqueous resin coating layer. Examples of the organic modified polyoxyalkylene include polyester modification, polyether modification, and aralkyl modification. Among them, a polyether modified polyoxyalkylene is particularly preferred. The amount of the organic modified polyoxyalkylene to be added is preferably 1% by mass or more, and more preferably 3% by mass or more. When the content of the organic modified polysiloxane is less than 1% by mass, the lubricity of the obtained second aqueous resin coating layer is not sufficiently improved, and the friction reducing effect is not sufficiently obtained. Moreover, if the content of the organic modified polyoxane exceeds When the amount is 20% by mass, the ratio to the second aqueous resin coating layer is too high, which adversely affects the properties such as corrosion resistance.

<Binder Resin>

The second water-based resin coating film-forming composition usually contains a binder resin for fixing a colloidal cerium oxide or a coloring pigment to the second water-based resin coating layer formed of the composition. The type of the binder resin is not particularly limited as long as it can fix the colloidal cerium oxide or the coloring pigment, and an acrylic resin, a urethane resin, a polyolefin resin, or a polyester system can be suitably used. A resin, a fluorine-based resin, a fluorene-based resin, and a mixed or modified resin thereof. Among them, a polyethylene resin or a polyurethane resin is preferable because it can effectively suppress secondary aggregation of the black pigment in the composition and obtain excellent liquid stability. The binder resin may be used singly or in combination of two or more.

In the 100% by mass of the total solid content of the second aqueous resin coating film-forming composition, the binder resin is preferably 15% by mass or more (more preferably 25% by mass or more) and 85% by mass or less (more preferably 75% by mass). % below)). When the content of the binder resin is less than 15% by mass, the film-forming property of the second aqueous resin coating layer is lowered, and the fixation of the colloidal cerium oxide or the coloring pigment in the second aqueous resin coating layer is insufficient, and coating occurs. The cloth is uneven and there is a problem that causes appearance problems. On the other hand, when the content of the binder resin is more than 85% by mass, the content of the colloidal cerium oxide or the coloring pigment is reduced, and it is difficult to absorb the black pigment which has passed through the first water-based resin coating layer. The light is sent back to the first water-based resin coating layer. To the full blackness.

In the second water-based resin coating layer, it is preferable to contain 25% by mass or more of the polyethylene resin, more preferably 30% by mass or more, particularly preferably, in view of the tape peeling property in the 2T bending celloline peeling test to be described later. It is 35 mass% or more. Since the adhesion to the tape is peculiar to the olefin resin, the peeling of the first aqueous resin coating layer is suppressed, so that the tape peeling property is increased.

The polyethylene resin is preferably an olefin-α,β-unsaturated carboxylic acid copolymer (hereinafter also referred to as "olefin-acid copolymer") or an α,β-unsaturated carboxylic acid polymer (hereinafter also referred to as " Carboxylic acid polymer") and An oxazoline group polymer. The olefin-acid copolymer and the carboxylic acid polymer do not impair the dispersion stability of the colloidal cerium oxide or the coloring pigment in the second water-based resin coating film-forming composition, and are excellent in barrier properties, thereby suppressing water to the first water system. The resin coating layer is impregnated to increase the corrosion resistance.

In addition, the "olefin-acid copolymer" in the present invention means a copolymer of an olefin and an α,β-unsaturated carboxylic acid, and a constituent unit derived from an olefin is 50% by mass or more in the copolymer (ie, The constituent unit derived from the α,β-unsaturated carboxylic acid is 50% by mass or less. Further, the term "carboxylic acid polymer" means a polymer obtained by polymerizing an α,β-unsaturated carboxylic acid as a monomer (including a copolymer), and a composition derived from an α,β-unsaturated carboxylic acid. The unit is 90% by mass or more of the polymer.

The above olefin-acid copolymer can be produced by copolymerizing an olefin with an α,β-unsaturated carboxylic acid by a known method, and is commercially available. The olefin-acid copolymer system may be used alone or in combination of two or more.

The olefin which can be used for the production of the olefin-acid copolymer is not particularly limited, but is preferably ethylene, propylene or the like, and more preferably ethylene. The olefin-acid copolymer-based olefin-forming unit may be derived from only one type of olefin, or may be derived from two or more types of olefins.

The α,β-unsaturated carboxylic acid which can be used for the production of the olefin-acid copolymer is not particularly limited, and examples thereof include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid; Dicarboxylic acid such as acid, fumaric acid or itaconic acid. Among these, acrylic acid is preferred. The olefin-acid copolymer-based α,β-unsaturated carboxylic acid may be derived from only one type of α,β-unsaturated carboxylic acid, or may be derived from two or more kinds of α,β-unsaturated carboxylic acids.

The α,β-unsaturated carboxylic acid unit in the olefin-acid copolymer functions to improve the adhesion between the first aqueous resin coating layer and the second aqueous resin coating layer, and the copolymer is effectively used to exhibit the effect. The unit amount of the α,β-unsaturated carboxylic acid is preferably 5% by mass or more, and more preferably 10% by mass or more. On the other hand, the upper limit of the unit amount of the α,β-unsaturated carboxylic acid in the copolymer is 50% by mass as described above, and particularly preferably 30% by mass or less, and particularly preferably 25% by mass, from the viewpoint of corrosion resistance. the following.

The olefin-acid copolymer may have a constituent unit derived from another monomer insofar as it does not adversely affect the secondary aggregation inhibition of the colloidal cerium oxide or the coloring pigment. In the olefin-acid copolymer, the constituent unit amount from the other monomer is preferably 10% by mass or less, more preferably 5% by mass or less, and the most preferred olefin-acid copolymer is only olefin and α, β- It is composed of a saturated carboxylic acid. A preferred example of the olefin-acid copolymer is an ethylene-acrylic acid copolymer.

The weight average molecular weight (Mw) of the above olefin-acid copolymer is preferably from 1,000 to 100,000, more preferably from 3,000 to 70,000, particularly preferably from 5,000 to 30,000, in terms of polystyrene. This Mw system can be determined by using polystyrene as a standard GPC.

The carboxylic acid polymer may, for example, be a copolymer of a homopolymer or a copolymer of one or more kinds of α,β-unsaturated carboxylic acids or other monomers (excluding olefins). Such a carboxylic acid polymer can be produced by a known method and is commercially available. One type or two or more types may be used for the carboxylic acid polymer.

In the α,β-unsaturated carboxylic acid which can be used for the production of a carboxylic acid polymer, the α,β-unsaturated carboxylic acid which can be exemplified by the user can be used for the synthesis of the above olefin-acid copolymer. Among these, acrylic acid and maleic acid are preferred, and maleic acid is more preferred.

The carboxylic acid polymer may contain a constituent unit derived from a monomer other than the α,β-unsaturated carboxylic acid, and the constituent unit amount derived from the other monomer is 10% by mass or less, preferably 5% by mass or less based on the polymer. More preferably, it is a carboxylic acid polymer composed only of an α,β-unsaturated carboxylic acid.

Examples of preferred carboxylic acid polymers include polyacrylic acid, polymethacrylic acid, acrylic acid-maleic acid copolymer, and polymaleic acid. Among them, the first aqueous resin coating layer is used. From the standpoint of adhesion, etc., it is more preferable to be polymaleic acid. The polymaleic acid further increases the adhesion between the first aqueous resin coating layer and the second aqueous resin coating layer due to the large amount of carboxyl groups.

The weight average molecular weight (Mw) of the carboxylic acid polymer is preferably from 500 to 30,000, more preferably from 800 to 10,000, in terms of polystyrene, and particularly preferably 900~3,000, the best is 1,000~2,000. This Mw system can be determined by using polystyrene as a standard GPC.

The content ratio (mass ratio) of the olefin-acid copolymer to the carboxylic acid polymer in the polyethylene resin is preferably from 1,000:1 to 10:1, more preferably from 200:1 to 20:1, and still more preferably 100: 1~25:1. When the content ratio of the carboxylic acid polymer is too low, the combined effect of the olefin-acid copolymer and the carboxylic acid polymer may not be sufficiently exhibited. Conversely, if the content ratio of the carboxylic acid polymer is excessive, the olefin-acid in the composition The copolymer is phase-separated from the carboxylic acid polymer, and the second aqueous resin coating layer layer is unevenly formed.

Above An oxazoline group polymer Oxazoline group, the The oxazoline group forms a dense network structure by crosslinking a carboxyl group with an olefin-acid copolymer or a carboxylic acid polymer to crosslink the resins. In this way, the barrier properties of the second aqueous resin coating layer are improved, and the penetration of water into the first aqueous resin coating layer is suppressed, and the corrosion resistance is improved.

As the above The oxazoline group polymer is preferably composed of styrene/acrylic acid. For example, in a commercial product, "Epocros (registered trademark)" manufactured by Nippon Shokubai Co., Ltd. is preferably used. As Epocros (registered trademark), the Epocros (registered trademark) K series is emulsified. The grades are K-2010E (Tg: -50 °C), K-2020E (Tg: 0 °C) and K-. 2030E (Tg: 50 ° C). Among them, in order to obtain a harder film, the best is "Epocros (registered trademark) K-2030E".

100 parts by mass (solid content) based on the total of the olefin-acid copolymer and the carboxylic acid polymer, The oxazoline group-containing polymer is preferably contained in an amount of 1 part by mass or more (more preferably 2 parts by mass or more, particularly preferably 3 parts by mass or more), more preferably 8 parts by mass or less (more preferably 7 parts by mass or less, It is especially preferably contained in an amount of 6 parts by mass or less, particularly preferably 4 parts by mass or less. Contain When the content of the oxazoline group polymer is less than the above range, the crosslinking reaction becomes insufficient, and the denseness of the formed second aqueous resin coating layer is not obtained, and as a result, the obtained aqueous resin coating film is laminated. The corrosion resistance of the board is poor. On the other hand, including When the content of the oxazoline group polymer is more than the above range, the functional group (carboxyl group) of the second aqueous resin coating layer is reduced by the excessive crosslinking reaction, and the adhesion to the first aqueous resin coating layer is improved. There is a situation of reduction.

In the first water-based resin coating layer, even when a polyethylene resin is contained, it can be adjusted in the same manner as described above.

<film thickness>

In the second water-based resin coating film layer of the present invention, the second water-based resin coating film-forming composition can be applied to one surface or both surfaces of the metal sheet to have a predetermined dry film thickness and dried. form.

The film thickness (dry film thickness) of the second aqueous resin coating layer is preferably 0.3 μm or more (more preferably 0.5 μm or more, and particularly preferably 0.9 μm or more) of 7.0 μm or less (more preferably 6.0 μm or less, and particularly preferably 5.0μm or less). When the film thickness of the second water-based resin coating layer is less than 0.3 μm, light that has not been absorbed by the black pigment of the first water-based resin coating layer is not sufficiently absorbed in the second water-based resin coating layer. It is difficult to sufficiently increase the blackness by reflecting light on the surface of the colloidal cerium oxide or the colored pigment and returning the light to the first water-based resin coating layer. On the other hand, if the film thickness of the second water-based resin coating layer is super When the thickness is 7.0 μm, the second aqueous resin coating layer is likely to be embossed, which tends to cause poor appearance. Moreover, the time taken for painting or drying becomes long, and the manufacturing cost increases.

[Total film thickness and ratio of the first water-based resin coating layer and the second water-based resin coating layer]

The total film thickness of the first water-based resin coating layer and the second water-based resin coating layer is 0.9 μm or more (preferably 1.0 μm or more, more preferably 1.3 μm or more) of 8.0 μm or less (preferably 7.0 μm or less, and more preferably Good for 6.0μm or less). When the total film thickness is less than 0.9 μm, the blackness of the first water-based resin coating film layer and the obtained water-based resin coating film laminated metal plate are insufficient. Moreover, by making the total film thickness 1.0 micrometer or more, it is easy to satisfy sufficient blackness and damage resistance. On the other hand, when the total film thickness is more than 8.0 μm, the blackness is excellent, but it is difficult to obtain a further improvement in blackness. On the other hand, wrinkles occur in the first water-based resin coating layer, and the second water-based resin is coated. A bulge occurs on the film layer, which is a poor appearance. Moreover, the time taken for painting or drying becomes long, and the manufacturing cost increases.

The film thickness of the first water-based resin coating layer is preferably 4 times or less the film thickness of the second water-based resin coating layer. The thicker the film thickness of the first water-based resin coating layer, the more the tape peeling resistance is lowered, and the thinner the film thickness of the second water-based resin coating layer, the more the tape peeling resistance is lowered. In addition, the higher the adhesion between the second water-based resin coating layer and the tape (the higher the concentration of the polyurethane resin having a high adhesiveness in the second water-based resin coating layer), the later-described When the 2T bending cymbal tape peeling test is carried out, the easier it is to peel off to the first water The black appearance after peeling is impaired until the resin coating layer is applied. When the total film thickness of the first water-based resin coating film layer and the second water-based resin coating film layer is within the above-specified range, regardless of the film thickness, the first water-based resin coating can be suppressed as long as it is within the film thickness ratio range. Peeling of the film layer.

[method]

The composition for forming a water-based resin coating film can be prepared by mixing the above components at a predetermined ratio. The mixing order is not particularly limited.

The method of applying and drying the aqueous resin coating film-forming composition in forming the water-based resin coating film layer is not particularly limited, and a known method can be suitably employed. Examples of the coating method of the composition include a bar coating method, a roll coating method, a curtain coating method, a spray method, a spray-wringer method, and the like. From the viewpoint, a bar coating method, a roll coating method, and a spray extrusion method are preferred. In addition, the drying temperature may be such that the water-based resin coating layer is not deteriorated by heat, and is preferably, for example, about 50 to 160 ° C, more preferably about 70 to 140 ° C.

Further, when a non-chromate-type chemical conversion film layer (base layer) is formed on the surface of a metal plate by a substrate treatment, if a film formation layer is applied by a roll coating method, a spray method, an immersion treatment method or the like, a film layer can be obtained. Non-chromate type coated laminated metal sheet.

[Blackness measurement]

The water-based resin coating film laminated metal plate has excellent blackness, and in the preferred aspect of the invention, the blackness of the water-based resin coating laminated metal plate (L *Value) is less than 23, more preferably less than 21. When the blackness (L* value) is 23 or more, it is difficult to say that it is beautiful black in visual observation. In the present invention, the L value is a lightness index of the measured value measured by the method specified in JIS Z8722, and can be measured by the method described in the examples below, and converted into an L* value according to the following formula.

L*=1.3632L-3.5904

[other]

In the opposite surface (hereinafter referred to as the back surface) of the surface to which the coating film is applied (described as the surface in the specification), it is preferable to laminate the coating film from the viewpoints of corrosion resistance, workability, and the like. Similarly to the surface, when a black appearance is required on the back surface, it is preferable to adjust the coating film and the laminate used in the present invention in accordance with the required degree of blackness.

The benefit of the priority based on Japanese Patent Application No. 2013-033817, filed on Feb. 22, 2013, and Japanese Patent Application No. 2013-204220, filed on Sep. 30, 2013. The entire contents of the specification of Japanese Patent Application No. 2013-03418, filed on Feb. 22, 2013, and the Japanese Patent Application No. 2013-204220, filed on Sep. 30, 2013, are hereby incorporated by reference in .

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples, but the following examples The present invention is not limited thereto, and a modified embodiment that does not depart from the gist of the present invention is included in the present invention. Hereinafter, "%" means "% by mass", and "part" means "parts by mass".

The evaluation method for each of the water-based resin coating film laminated metal sheets described below is as follows.

[Evaluation method] (1) uneven coating

The coated sample was cut into 50 × 120 mm so that the coating direction became the longitudinal direction, and the surface was visually observed, and the occurrence state of uneven coating was evaluated by the following evaluation criteria.

A: No uneven coating

B: uneven coating

(2) Hue (blackness evaluation)

The L value of the test material of the water-based resin coating laminated metal plate was measured using a spectrophotometer ("Spectro Color Meter SQ2000" manufactured by Nippon Denshoku Industries Co., Ltd.), and the obtained L value was converted into an L* value according to the following formula. , by which to evaluate the blackness.

L*=1.3632L-3.5904

From the value of the L* value, the blackness of the test material was evaluated by the following evaluation criteria.

A: L* value is less than 21

B: L* value is 21 or more and less than 23

C: L* value is 23 or more

(3) wrinkles

The coated sample was cut into 50 × 120 mm so that the coating direction became the longitudinal direction, and the surface was visually observed, and the state of occurrence of wrinkles was evaluated by the following evaluation criteria.

A: no wrinkles

B: Partially see the crepe-like wrinkles

C: Comprehensively see the crepe-like wrinkles

(4) bulge

The second aqueous resin coating layer was applied, and after drying, the presence or absence of protrusion was observed by a microscope at a magnification of 175 times in a field of 1.5 × 2.0 mm, and evaluated by the following evaluation criteria.

A: no protrusion in the range of the above field of view

C The number of protrusions in the range of the above field of view is less than 5

B The number of protrusions in the range of the above field of view is 5 or more

(5) Damage resistance

Using a surface tester ("Tribogear (registered trademark) HEIDON-140 DR" manufactured by Shinto Scientific Co., Ltd.), a sapphire scratching needle (tip radius of curvature: 0.075 mm) was used to load the test material at room temperature. The specified load, the sliding speed was 100 mm/min, and the sliding distance was 20 mm. After scratching once, it was evaluated whether or not there was damage on the surface of the water-based resin coating laminated metal plate. At 10, 15, 20, 25, ‧ ‧ g, the above load is increased every 5 g, and the maximum load without damage is taken as the measurement result.

The damage resistance of the test piece was evaluated by the following evaluation criteria from the maximum load without damage.

A: above 85gf

B: 60gf or more and less than 85gf

C: less than 60gf

Further, as a comparative material, a black PCM in which a top coat layer having a film thickness of 6.0 μm was laminated on an undercoat layer having a film thickness of 1.0 μm was used, and the same measurement as described above was carried out, and the maximum load without damage was 60 gf. The above black PCM is produced by the following method. First, a solvent-based primer ("NC66-59 primer" manufactured by FINE COATINGS, Japan) was diluted with a diluent (xylene: cyclohexanone = 50:50) so as to have a film thickness of 1.0 μm. The coater was coated on an electrogalvanized metal plate and dried by heating at 205 ° C for 60 seconds to form an undercoat layer. Then, the solvent-based black top coat layer ("FLC495 black" manufactured by FINE COATINGS, Japan) was diluted with the above-mentioned diluent so as to have a film thickness of 6.0 μm, and then applied to the undercoat layer by a bar coater. The film was dried by heating at 250 ° C for 60 seconds to form a top coat layer, which became a black PCM having a total film thickness of 7.0 μm.

(6) Stripping

The water-based resin coating laminated metal sheet was subjected to 2T bending, and a celluloid tape (Cellotape (registered trademark) CT405AP-24 manufactured by NICHIBAN) was adhered to the processed portion, and the celluloid tape was peeled off, and the first water system of the black layer was visually observed. The presence or absence of peeling test of the resin coating layer (2T bending cellophane tape peeling test) was evaluated by the following evaluation criteria.

A: no peeling

B: a bit peeling

[Production of substrate treated metal sheet]

First, about 952 parts of pure water, acidic colloidal cerium oxide ("Snowtex (registered trademark) O" manufactured by Nissan Chemical Co., Ltd.; solid content 20% by mass) 26.3 parts and aluminum dihydrogen phosphate (manufactured by Mishan Chemical Co., Ltd.; 50 parts by mass of the component: 19.5 parts, and polyacrylic acid (Jurymer (registered trademark) AC-10-LP, manufactured by Nippon Pure Chemical Co., Ltd.; solid content 100% by mass) 0.75 parts, and a decane coupling agent (Shin-Etsu Chemical Co., Ltd.) was added thereto. A "KBM403"; solid content of 100% by mass) of 1.13 parts was prepared, and a composition of the substrate treatment composition (solid content concentration: 1.7% by mass) was prepared.

Next, the obtained substrate treatment composition solution was applied to the front and back surfaces of an electrogalvanized metal plate (EG; Zn adhesion amount: 20 g/m ² ) having a thickness of 0.45 mm by a manual roll coating apparatus to have a dry mass of 103 mg/ m ^{2 was} then dried at 220 ° C for 12 seconds to prepare a substrate-treated metal plate. Hereinafter, the metal plate EG is treated as a substrate using an electrogalvanized metal plate.

[Additive for improving blackness]

At least one of the colloidal cerium oxide and various pigments described in Table 1 is contained in the second aqueous resin coating layer. "Snowtex (registered trademark) XS" manufactured by Nissan Chemical Industries Co., Ltd. with a particle size of 4 to 6 nm (nominal value) is used as colloidal cerium oxide A, and Nissan Chemical Industry Co., Ltd. has a particle size of 10 to 20 nm (nominal value). The company "Snowtex (registered trademark) 40" is used as colloidal cerium oxide B. The details are as follows.

[Production of Polyurethane Resin Composition Forming First Water-Based Resin Coating Layer and Method of Forming Metal Plate Containing Polyurethane-Based First Water-Based Resin Coating Layer] (About No.1~11 and No.23~24)

In the autoclave (content: 1.0 L) having an emulsification apparatus equipped with a stirrer, a thermometer, and a temperature controller, polytetramethylene ether glycol (manufactured by Hodogaya Chemical Industry Co., Ltd., having a number average molecular weight of 1,000) was added as a polyol component. 60 g, 14 g of 1,4-cyclohexanedimethanol, and 20 g of dimethylolpropionic acid were added, and 30.0 g of N-methylpyrrolidone as a reaction solvent was further added. 104 g of toluene diisocyanate which is an isocyanate component was added, and the temperature was raised to 80-85 degreeC, and it was set as the reaction for 5 hours. The NCO content of the obtained prepolymer was 8.9%. Further, 16 g of triethylamine was added and neutralized, and a mixed aqueous solution of 16 g of ethylenediamine and 480 g of water was added, and the mixture was emulsified at 50 ° C for 4 hours to carry out chain extension reaction. An aqueous dispersion in which a carboxyl group-containing polyurethane resin was dispersed (nonvolatile resin component 29.1%, acid value 41.4. Hereinafter referred to as a polyurethane resin aqueous solution).

In the aqueous solution of the polyurethane resin obtained above, an epoxy-based crosslinking agent ("Epiclon (registered trademark) CR75" manufactured by DIC Corporation), colloidal cerium oxide A, and glycidoxy-containing oxy group are sequentially added. A decane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd.: 100% solid content), black pigment (ink: "Ultra-rich ink drop BA-8" manufactured by Kuretakes Co., Ltd., or carbon black 1: manufactured by Yuki Co., Ltd. In the "SA black DY-6"), a polyurethane resin composition for forming a first water-based resin coating layer is prepared. The compounding ratio of each component is blended in such a manner that the solid content is 57.5 parts of a polyurethane resin, 2.5 parts of an epoxy-based crosslinking agent, 10 parts of colloidal cerium oxide, and 30 parts of a black pigment. The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water to adjust the solid concentration to 10%, and the mixture was stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 1.0 μm, dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds), and a polyurethane-containing film is formed on the metal plate. The first aqueous resin coating layer.

(About No.27~60)

The epoxy-based crosslinking agent, colloidal cerium oxide A, black pigment (ink, or ink, and carbon black 1) are added in this order to the aqueous solution of the polyurethane resin obtained above, and the first aqueous system is prepared. Resin coating layer forming polyamine group Formate resin composition. The compounding ratio of each component is 45.1 to 63.2 parts of the polyurethane resin, 2.0 to 2.8 parts of the epoxy crosslinking agent, 7.9 to 11 parts of the colloidal ceria, and 23 to 45 parts of the black pigment in terms of solid content. The way to match. The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water to adjust the solid concentration to 10%, and the mixture was stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 0.7 to 1.2 μm, and dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to form a polyaminocarboxylic acid on the metal plate. The first aqueous resin coating layer of the ester.

(About No.69~111)

In the aqueous solution of the polyurethane resin obtained above, the epoxy-based crosslinking agent, the colloidal ceria A, and the black pigment (ink and carbon black 1) are added in this order to prepare the first aqueous resin coating film. The layer forming polyurethane resin composition. The compounding ratio of each component is 45.1 to 63.2 parts of polyurethane resin, 2.0 to 2.8 parts of epoxy crosslinking agent, and 7.9 to 11 of colloidal cerium oxide in terms of solid content. It is blended in a ratio of 23 to 45 parts of black pigment. The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water to adjust the solid concentration to 15%, and the mixture was stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 0.9 to 7.5 μm, and dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to form a polyaminocarboxylic acid on the metal plate. The first aqueous resin coating layer of the ester.

(About No.112~150)

In the aqueous solution of the polyurethane resin obtained above, the epoxy crosslinking agent, the colloidal ceria A, and the black pigment (ink and carbon black 1) are added in this order, and in No. 112 to 114, The aqueous polyurethane resin solution to be described later is added to prepare a polyurethane resin composition for forming a first aqueous resin coating film layer. The compounding ratio of each component is 28.0 to 67.0 parts of polyurethane resin, 0.0 to 29.0 parts of polyethylene resin, 0.0 to 7.5 parts of epoxy crosslinking agent, and colloidal cerium oxide 1~ in terms of solid content. 40 parts, 30 parts of black pigment (ink: 20 parts, carbon black 1: 10 parts). The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water, adjusted to a solid concentration of 10%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 1.0 μm, dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds), and a polyurethane-containing film is formed on the metal plate. The first aqueous resin coating layer.

(About No.151~191)

In the aqueous solution of the polyurethane resin obtained above, the epoxy-based crosslinking agent, the colloidal ceria A, and the black pigment (ink and carbon black 1) are added in this order to prepare the first aqueous resin coating film. The layer forming polyurethane resin composition. The blending ratio of each component is 57.5 parts of a polyurethane resin, 2.5 parts of an epoxy-based crosslinking agent, 10 parts of colloidal cerium oxide, and 30 parts of a black pigment in terms of solid content (ink: 20 parts, carbon) Black 1:10) The way to cooperate. The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water to adjust the solid concentration to 15%, and the mixture was stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 0.7 to 6.6 μm, and dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to form a polyaminocarboxylic acid on the metal plate. The first aqueous resin coating layer of the ester.

(About No.192~206, No.209~235)

In the aqueous solution of the polyurethane resin obtained above, the epoxy-based crosslinking agent, the colloidal ceria A, and the black pigment (carbon black 1) are added in this order to prepare a first aqueous resin coating layer. A polyurethane resin composition is used. The compounding ratio of each component is 61.2 to 76.0 parts of the polyurethane resin, 1.0 to 4.0 parts of the epoxy crosslinking agent, 3.0 to 18 parts of the colloidal cerium oxide, and 17 to 25 parts of the black pigment in terms of solid content. The way to match. The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water to adjust the solid concentration to 15%, and the mixture was stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 0.7 to 4.9 μm, and dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to form a polyaminocarboxylic acid on the metal plate. The first aqueous resin coating layer of the ester.

(About No. 207~208)

In the aqueous solution of the polyurethane resin obtained above, the above epoxy crosslinking agent, colloidal cerium oxide A, black pigment (carbon black) are sequentially added. 2: "SA Black E-1319" manufactured by Yuki Co., Ltd. or Carbon Black 3: "GP Black 1188" manufactured by Yuki Co., Ltd.), and the first water-based resin coating layer is formed into a polyurethane resin. Things. The compounding ratio of each component is 71.0 parts of a polyurethane resin, 5.0 parts of an epoxy crosslinking agent, 5.0 parts of colloidal cerium oxide, and black pigment (carbon black 2 or carbon black 3) in terms of solid content. 19 copies of the way. The composition of the first aqueous resin coating layer forming polyurethane resin was diluted with pure water to adjust the solid concentration to 15%, and the mixture was stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a bar coater. The substrate is treated on the surface of the metal plate EG so as to have a film thickness of 1.2 μm, dried at a plate temperature of about 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds), and a polyurethane-containing film is formed on the metal plate. The first aqueous resin coating layer.

[Production of Polyethylene Resin Composition Forming First Water-Based Resin Coating Layer and Method of Forming Metal Plate Having First Water-Based Resin Coating Layer Containing Polyethylene] (About No.12~22 and No.25~26)

An ethylene-acrylic acid copolymer ("Primacor (registered trademark) 5990I" manufactured by DOW Chemical Co., Ltd., a constituent unit derived from acrylic acid: 20%, mass average molecular weight, was added to an autoclave equipped with an emulsifier equipped with a stirrer, a thermometer, and a temperature controller. (Mw): 20,000, melt index: 1300, acid value: 150) 200.0 parts, polymaleic acid aqueous solution (Nonpol (registered trademark) PMA-50W manufactured by NOF Corporation, Mw: about 1100 (in terms of polystyrene) , 50% of the product 8.0 parts, 35.5 parts of triethylamine (relative to the carboxyl group of the ethylene-acrylic acid copolymer, 0.63 equivalent), and 6.9 parts of the 48% NaOH aqueous solution (relative 3.5 parts of a carboxyl group of an ethylene-acrylic acid copolymer, a tall oil fatty acid ("Hartall FA3" manufactured by HARIMA Chemical Co., Ltd.), and 792.6 parts of ion-exchanged water were sealed, and stirred at a high speed at 150 ° C and 5 atmospheres. Cool down to 30 hours. Next, a cyclopropane coupling agent containing a glycidoxy group ("TSL8350", γ-glycidoxypropyltrimethoxydecane) manufactured by Momentive Functional Materials (formerly known as GE Toshiba SILICONE) was added, and was contained in an amount of 10.4 parts. A carbodiimide-based compound (Carbodilite (registered trademark) SV-02, manufactured by Nisshin Chemical Co., Ltd., polycarbodiimide, Mw: 2,700, 40% solid content) 31.2 parts, 72.8 parts of ion-exchanged water, stirred for 10 minutes An emulsion (emulsion) of an olefin-acid copolymer and a carboxylic acid polymer (solid content concentration: about 20%, measured in accordance with JIS K6833) to obtain an aqueous dispersion in which a polyethylene resin is dispersed (hereinafter referred to as a polyethylene resin aqueous solution) liquid).

In the aqueous solution of the polyethylene resin obtained above, a black pigment (ink or carbon black 1), a colloidal ruthenium dioxide A, and a decane coupling agent containing a glycidoxy group (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) were added in this order: Solid content concentration 100%), including The oxazoline group polymer ("Epocros (registered trademark) K-2030E" manufactured by Nippon Shokubai Co., Ltd.: 40% solid content) was prepared to prepare a polyethylene resin composition for forming a first water-based resin coating layer. The compounding ratio of each component is 53.2 parts of polyethylene resin, 30 parts of black pigment, 9.3 parts of colloidal cerium oxide, and 4.7 parts of decane coupling agent, in terms of solid content. The oxazoline group polymer was blended in such a manner as to be 2.8 parts. The polyethylene resin composition for forming a first water-based resin coating layer was diluted with pure water, adjusted to a solid concentration of 10%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to a substrate-treated metal sheet by a bar coater. On the surface of the EG, a film thickness of 1.0 μm was applied and dried at a plate temperature of 120 to 130 ° C (temperature of 220 ° C × 12 seconds) to form a first water-based resin coating film containing polyethylene on the substrate-treated metal plate EG. Floor.

(About No.61~68)

In the aqueous solution of the polyethylene resin obtained above, black pigment (ink only), colloidal ruthenium dioxide A, the above-mentioned glycidoxy-containing decane coupling agent, and the above-mentioned The oxazoline group polymer is used to prepare a polyethylene resin composition for forming a first aqueous resin coating layer. The compounding ratio of each component is 53.2 parts of polyethylene resin, 30 parts of black pigment, 9.3 parts of colloidal cerium oxide, and 4.7 parts of decane coupling agent, in terms of solid content. The oxazoline group polymer was blended in such a manner as to be 2.8 parts. The polyethylene resin composition for forming a first water-based resin coating layer was diluted with pure water, adjusted to a solid concentration of 10%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to a substrate-treated metal sheet by a bar coater. On the surface of the EG, the film thickness is 0.7 to 1.2 μm, and the plate temperature is 120 to 130 ° C (the furnace temperature is 220 ° C × 12 seconds), and the first water-based resin containing polyethylene is formed on the substrate-treated metal plate EG. Coating layer.

[Production of Polyurethane Resin Composition Forming Second Water-Based Resin Coating Layer and Method of Forming Metal Plate Containing Polyurethane-Based Second Water-Based Resin Coating Layer] (About No. 23~26)

In the aqueous solution of the polyurethane resin obtained above, the above-mentioned epoxy-based crosslinking agent, colloidal cerium oxide B, and polyamine-based shaking agent (Disparlon (registered trademark) AQ manufactured by Nanben Chemical Co., Ltd.) are added in this order. -607: a polyurethane component resin composition for forming a second aqueous resin coating layer is prepared by a solid concentration of 15%, hereinafter referred to as polyamine. The blending ratio of each component was adjusted so as to be 77.8 parts of a polyurethane resin, 2 parts of an epoxy-based crosslinking agent, 20 parts of colloidal cerium oxide, and 0.2 parts of polydecylamine in terms of solid content. The composition of the polyurethane resin layer for forming a second aqueous resin coating layer was diluted with pure water, adjusted to a solid concentration of 15%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied by a roll coater. The film thickness of the first water-based resin coating layer was 1.0 μm, and the film was heated and dried at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain a film formed on the first water-based resin coating layer. A coated metal sheet of a second aqueous resin coating layer containing a polyurethane.

(About No.27~36, 49~50, 56 and No.67~68)

The epoxy-based crosslinking agent and the additive for improving the blackness (colloidal cerium oxide B, cyan, or colloidal cerium oxide B, cyan) are added in this order to the aqueous solution of the polyurethane resin obtained above. Blue and two The mixture of purple and the above polyamine is used to prepare a polyurethane resin composition for forming a second aqueous resin coating layer. The compounding ratio of each component is 68.1 to 87.8 parts of the polyurethane resin, 1.7 to 2.2 parts of the epoxy crosslinking agent, 10 to 30 parts of the additive, 0 part or 0.2 part of the polyamide. The way to cooperate. The composition of the polyurethane resin for forming a second aqueous resin coating layer was diluted with pure water to adjust the solid concentration to 10 to 15%, and the mixture was stirred at 700 rpm for 10 minutes using a dispersing mixer, and then coated by a roll coater. It is placed on the first water-based resin coating layer to have a film thickness of 0.6 to 1.6 μm, and is heated and dried at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain a first water-based resin coating film. A coated metal sheet of a second aqueous resin coating layer containing a polyurethane is formed on the layer.

[Preparation of a polyethylene resin composition for forming a second aqueous resin coating layer and formation of a metal sheet comprising a second water-based resin coating layer containing polyethylene] (About No.1~22)

Add 626 parts of water and 160 parts of ethylene-acrylic acid copolymer (20% acrylic acid, melt index (MI) 300) to the autoclave, and add 40 mol% of triethylamine and 15 mol% of NaOH at 150 ° C, 5 Pa. The mixture was stirred at a high speed to obtain an emulsion of an ethylene-acrylic acid copolymer. Next, 4,4'-bis(extended ethyliminocarbonylamino group) as an internal crosslinking agent was added to the above emulsion as a solid crosslinking agent of 5% (the solid content of the emulsion composition was 100%). Diphenylmethane ("Chemitite (registered trademark) DZ-22E" manufactured by Nippon Shokubai Co., Ltd.) to obtain an emulsion mixture.

In the emulsion mixture obtained above, a epoxy propyl group-containing compound A ("Epiclon CR5L" manufactured by DIC Corporation), a colloidal cerium oxide A as an additive for improving the degree of blackness, or various kinds are added in this order. Coloring pigments (ink, carbon black 1, titanium oxide, cyan, quinacridone red, turquoise, two "Purple", a polyamidamide-based shaker (Disparlon (registered trademark) AQ-607, manufactured by Kwanmoto Kasei Co., Ltd.: solid content concentration: 15%. Hereinafter, polyamine), and preparation of a second aqueous resin coating layer formation polymerization Vinyl resin composition. The compounding ratio of each component is blended in an amount of 64.8 or 65 parts of the emulsion mixture, 5 parts of a crosslinking agent, 30 parts of an additive, and 0 or 0.2 parts of polyamine. The polyethylene resin composition for forming a second aqueous resin coating layer was diluted with pure water, adjusted to a solid concentration of 10%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to the first aqueous resin by a roll coater. On the coating layer, the film thickness was 1.0 μm, and the sheet was heated and dried at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain a polyethylene-containing resin layer on the first water-based resin coating layer. A coating film of a second water-based resin coating layer is laminated.

(About No.37~48, 51~55, 57~66)

In the emulsion mixture obtained above, the above-mentioned epoxy group-containing compound A and an additive for improving the blackness (a mixture of colloidal cerium oxide A, cyan blue, cyan, colloidal cerium oxide A and cyan blue) are sequentially added. Further, the polyamine is used to prepare a polyethylene resin composition for forming a second aqueous resin coating layer. The compounding ratio of each component is adjusted to be 27.1 to 86.4 parts of the emulsion mixture, 2.7 to 8.6 parts of the crosslinking agent, 5 to 70 parts of the additive, and 0 or 0.2 parts of the polyamine. The polyethylene resin composition for forming the second aqueous resin coating layer was diluted with pure water to adjust the solid concentration to 7 to 15%, and the mixture was stirred at 700 rpm for 10 minutes with a dispersing mixer, and then applied to the first by a roll coater. The film thickness of the water-based resin coating layer is 0.4 to 1.3 μm, and is dried by heating at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain a film formed on the first water-based resin coating layer. Polyethylene A coating film of a second aqueous resin coating layer of an olefin is laminated.

(About No.69~111)

In the emulsion mixture obtained above, the above-mentioned epoxy group-containing compound A and an additive for improving the blackness (colloidal ceria A, cyan, cyan, colloidal ceria A and cyanine are added in this order, A polyethylene resin composition for forming a second aqueous resin coating layer is prepared by mixing polyamine with a mixture of colloidal cerium oxide A and cyan. The compounding ratio of each component is blended in an amount of 64.8 to 88.2 parts of the emulsion mixture, 5 to 6.8 parts of the crosslinking agent, 5 to 30 parts of the additive, and 0 or 0.2 parts of the polyamine. The polyethylene resin composition for forming a second aqueous resin coating layer was diluted with pure water, adjusted to a solid concentration of 15%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to the first aqueous resin by a bar coater. On the coating layer, the film thickness is 1.0 to 7.4 μm, and the substrate is heated at a plate temperature of 120 to 130 ° C (furnace temperature: 220 ° C × 12 seconds) to obtain a polycondensate formed on the first water-based resin coating layer. A coating film of a second aqueous resin coating layer of ethylene is laminated.

(About No.112~150)

In the aqueous solution of the polyethylene resin, a compound containing a propyl group as an external crosslinking agent ("Epiclon CR75" manufactured by DIC Corporation) and an additive for improving the degree of blackness (colloidal cerium oxide A, green) are sequentially added. Blue, green), polyamine, and polyethylene wax particles ("Chemipearl (registered trademark) W-700" manufactured by Mitsui Chemicals Co., Ltd., average particle size 1 μm, soft Chemical point 132 ° C) or polyoxyalkylene-based lubricant (polyether modified polydimethyl siloxane: "BYK-307" manufactured by BYK Chemical Co., Ltd." and "BYK-337" manufactured by BYK Chemical Co., Ltd., polyether Ester-modified polyoxymethylene oxide containing hydroxyl group: "BYK-375" manufactured by BYK Chemical Co., Ltd., and then aqueous solution of polyurethane resin is added to No. 123-127. 2 A polyethylene resin composition for forming a water-based resin coating layer. The compounding ratio of each component is 0.0 to 79.0 parts of polyethylene resin, 0.0 to 59.0 parts of polyurethane resin, 0.0 to 17.5 parts of crosslinking agent, 10 to 70 parts of additive, and polyethylene wax in terms of solid content. The particles were mixed in such a manner that the particles were 1.8 to 9.8 parts, or 1.8 or 9.8 parts of a polyoxyalkylene-based lubricant, and 0.2 parts of polyamine. The polyethylene resin composition for forming a second aqueous resin coating layer was diluted with pure water, adjusted to a solid concentration of 10%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to the first aqueous resin by a roll coater. On the coating layer, the film thickness was 1.0 μm, and the sheet was heated and dried at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain polyethylene-containing film on the first water-based resin coating layer. A coating film of a second water-based resin coating layer is laminated.

(About No.151~191)

The epoxy group-containing compound B, the additive for improving the blackness (colloidal cerium oxide A, cyan, and cyan), the polyethylene wax particles, and the above polyfluorene are sequentially added to the aqueous solution of the polyethylene resin. A polyethylene resin composition for forming a second aqueous resin coating layer is prepared by using an amine. The compounding ratio of each component is converted into a solid resin in terms of solid content, which is 59.0. The mixture was mixed with 7.5 parts of a crosslinking agent, 30 parts of an additive, 3.3 parts of polyethylene wax particles, and 0.2 parts of polyamidamide. The polyethylene resin composition for forming a second aqueous resin coating layer was diluted with pure water, adjusted to a solid concentration of 15%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to the first aqueous resin by a bar coater. On the coating layer, the film thickness is 0.4 to 6.5 μm, and the sheet is heated and dried at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain a polycondensate formed on the first water-based resin coating layer. A coating film of a second aqueous resin coating layer of ethylene is laminated.

(About No.192~235)

In the aqueous solution of the polyethylene resin, the epoxy group-containing compound B, the additive for improving the blackness (colloidal cerium oxide A), the polyethylene wax particles, and the polyamine are added in this order, and the preparation is carried out. 2 A polyethylene resin composition for forming a water-based resin coating layer. The compounding ratio of each component is 59.0 parts of polyethylene resin, 0.0 part of polyurethane resin, 7.5 parts of crosslinking agent, 30 parts of additives, 3.3 parts of polyethylene wax particles, and polyamine 0.2 in terms of solid content. The way to match. The polyethylene resin composition for forming a second aqueous resin coating layer was diluted with pure water, adjusted to a solid concentration of 10%, and stirred at 700 rpm for 10 minutes in a dispersing mixer, and then applied to the first aqueous resin by a roll coater. On the coating layer, the film thickness is 0.7 to 1.3 μm, and the sheet is heated at a plate temperature of 120 to 130 ° C (furnace temperature of 220 ° C × 12 seconds) to obtain a polycondensate formed on the first water-based resin coating layer. A coating film of a second aqueous resin coating layer of ethylene is laminated.

[Industry use possibility]

According to the present invention, it is possible to provide a water-based resin coating film laminated metal sheet excellent in blackness and appearance. Therefore, the beautiful and black water-based resin coating laminated metal sheet of the present invention which is manufactured at low cost can be applied to a casing or a built-in ‧ exterior parts, steel furniture, etc. Building materials, etc.

Claims (12)

A water-based resin coating film laminated metal sheet characterized in that a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and a layer containing 3 masses is provided on the upper side of the first water-based resin coating layer The second water-based resin coating layer of the transparent coating layer of % or more of colloidal cerium oxide. A water-based resin coating film laminated metal sheet characterized in that a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and the layer is blue on the upper side of the first water-based resin coating layer The content of the blue pigment and the green pigment in the second water-based resin coating layer is 3% by mass or more in total of at least one of the pigment or the green pigment and the second aqueous resin coating layer of the polyamine-based rocking agent. A water-based resin coating film laminated metal sheet characterized in that a first water-based resin coating layer containing a black pigment is laminated on at least one surface of the metal sheet, and the layer is blue on the upper side of the first water-based resin coating layer a second aqueous resin coating layer of at least one of a pigment or a green pigment, a colloidal cerium oxide, and a polyamidamide-based squeezing agent, wherein the total content of the blue pigment and the green pigment in the second aqueous resin coating layer is The content of the colloidal cerium oxide in the second aqueous resin coating layer is 3% by mass or more. The water-based resin coating film laminated metal sheet according to any one of claims 1 to 3, wherein a total thickness of the first water-based resin coating layer and the second water-based resin coating layer is 0.9 to 8.0 μm. The water-based resin coating film laminated metal sheet according to any one of claims 1 to 3, wherein the lightness L* in the L*a*b* color system of the water-based resin coating laminated metal sheet is less than 23. The water-based resin coating film-coated metal sheet according to any one of the above-mentioned items, wherein the black pigment contained in the first water-based resin coating layer is 16% by mass or more and 50% by mass or less. The water-based resin coating laminated metal sheet according to any one of claims 1 to 3, wherein at least one of the black pigment-based ink or the carbon black contained in the first water-based resin coating layer is used. The water-based resin coating film laminated metal sheet according to any one of claims 1 to 3, wherein the first water-based resin coating layer contains 25% by mass or more of a polyurethane resin. The water-based resin coating film-layered metal sheet according to any one of claims 1 to 3, wherein the first water-based resin coating layer is a first water-based resin coating film-forming composition containing 1% by mass or more of a crosslinking agent. The winner. The water-based resin coating film laminated metal sheet according to any one of claims 1 to 3, wherein the second water-based resin coating layer does not contain a black pigment. The water-based resin coating film laminated metal sheet according to any one of claims 1 to 3, wherein the second water-based resin coating layer contains 25% by mass or more of a polyethylene resin, and the film of the first water-based resin coating layer The film thickness of the second aqueous resin coating layer is not more than 4 times. The water-based resin coating laminated metal sheet according to any one of claims 1 to 3, wherein the metal sheet is an electrogalvanized metal sheet.